Method for manufacturing semiconductor device

Abstract

A method for manufacturing a semiconductor device includes forming a first insulating film on a substrate, forming a second insulating film on the first insulating film, and forming a gate electrode on the second insulating film. Forming the second insulating film includes supplying film-forming materials and adsorbing the film-forming materials on the first insulating film, purging the film-forming materials that have not been adsorbed, supplying oxidants to oxidize the adsorbed film-forming materials, and purging the oxidants that have not contributed to oxidization. Forming the second insulating film is repeated in cycles, continuously, and the purging time of the oxidants in an initial number of the cycles is longer than the purging time of the oxidants in cycles following the initial number of cycles.

1. A method for manufacturing a semiconductor device comprising:
 forming a first insulating film on a substrate; 
 forming a second insulating film on the first insulating film in a plurality of repeated and continuous cycles, each cycle comprising:
 supplying film-forming materials and adsorbing the film-forming materials on the first insulating film; 
 purging the film-forming materials that have not been adsorbed; 
 supplying oxidants to oxidize the adsorbed film-forming materials; and 
 purging the oxidants that have not contributed to oxidization wherein, in purging the oxidants, purging for first purging times in an initial number of the plurality of cycles, the first purging times being longer than second purging times of purging the oxidants in the cycles after the initial number of cycles; and 
 
 forming a gate electrode on the second insulating film. 
 
     
     
       2. The method for manufacturing a semiconductor device according to  claim 1 , wherein the first purging times for purging the oxidants in the initial number of cycles is 5 to 15 times longer than the purging times of the oxidants in the cycles after the initial number of cycles. 
     
     
       3. The method for manufacturing a semiconductor device according to  claim 1 , wherein the second insulating film is selected from the group consisting of HfO 2 , HfAlO x , HfSiO x , and nitrides thereof. 
     
     
       4. The method for manufacturing a semiconductor device according to  claim 1 , wherein the initial number of cycles is 10 to 20 cycles. 
     
     
       5. The method for manufacturing a semiconductor device according to  claim 1 , comprising supplying a larger quantity of the oxidants in the initial number of the plurality of cycles than in the cycles after the initial number of cycles. 
     
     
       6. The method for manufacturing a semiconductor device according to  claim 5 , wherein the quantity of the oxidants supplied in the initial number of cycles is 2 to 3 times larger than the quantity of the oxidants supplied in the cycles after the initial number of cycles. 
     
     
       7. The method for manufacturing a semiconductor device according to  claim 5 , wherein the second insulating film is selected from the group consisting of HfO 2 , HfAlO x , HfSiO x , and nitrides thereof. 
     
     
       8. The method for manufacturing a semiconductor device according to  claim 5 , wherein the initial number of cycles is 5 to 20 cycles. 
     
     
       9. The method for manufacturing a semiconductor device according to  claim 1 , comprising supplying the oxidants in a plurality of separate cycles, in an initial number of the plurality of cycles larger in number than the number of cycles following the initial number of cycles. 
     
     
       10. The method for manufacturing a semiconductor device according to  claim 9 , wherein the number of the separate cycles of supplying the oxidants in the initial number of cycles is 2 to 3 times larger than the number of the cycles of supplying the oxidants in the cycles following the initial number of cycles. 
     
     
       11. The method for manufacturing a semiconductor device according to  claim 9 , wherein the second insulating film is selected from the group consisting of HfO 2 , HfAlO x , HfSiO x , and nitrides thereof. 
     
     
       12. The method for manufacturing a semiconductor device according to  claim 9 , wherein the initial number of cycles is 5 to 20 cycles. 
     
     
       13. A method for manufacturing a semiconductor device comprising:
 forming a first insulating film on a substrate; 
 forming a second insulating film on the first insulating film in a plurality of repeated and continuous cycles, each cycle comprising:
 supplying film-forming materials and adsorbing the film-forming materials on the first insulating film; 
 purging the film-forming materials that have not been adsorbed; 
 supplying oxidants to oxidize the adsorbed film-forming materials; and 
 purging the oxidants that have not contributed to oxidization wherein, in purging the film-forming materials, purging for first purging times in an initial number of the plurality of cycles, the first purging times being longer than second purging times of purging the film-forming materials in the cycles after the initial number of cycles; and 
 
 forming a gate electrode on the second insulating film. 
 
     
     
       14. The method for manufacturing a semiconductor device according to  claim 13 , wherein the first purging times for purging the film-forming materials in the initial number of cycles is 5 to 10 times longer than the second purging times of the film-forming materials in the cycles after the initial number of cycles. 
     
     
       15. The method for manufacturing a semiconductor device according to  claim 13 , wherein the second insulating film is selected from the group consisting of HfO 2 , HfAlO x , HfSiO x , and nitrides thereof. 
     
     
       16. The method for manufacturing a semiconductor device according to  claim 13 , wherein the initial number of cycles is 5 to 20 cycles. 
     
     
       17. A method for manufacturing a semiconductor device comprising:
 forming a first insulating film on a substrate; 
 forming a second insulating film on the first insulating film in a plurality of repeated and continuous cycles, each cycle comprising:
 supplying film-forming materials and adsorbing the film-forming materials on the first insulating film; 
 purging the film-forming materials that have not been adsorbed; 
 supplying oxidants to oxidize the adsorbed film-forming materials; and 
 purging the oxidants that have not contributed to oxidization wherein,
 in purging the film-forming materials, purging for first purging times in an initial number of the plurality of cycles, the first purging times being longer than second purging times of purging the film-forming materials in the cycles after the initial number of cycles, and 
 in purging the oxidants, purging for third purging times in the initial number of the plurality of cycles, the third purging times being longer than fourth purging times of purging the oxidants in the cycles after the initial number of cycles; and 
 
 
 forming a gate electrode on the second insulating film. 
 
     
     
       18. The method for manufacturing a semiconductor device according to  claim 17 , wherein
 the third purging times of the oxidants in the initial number of cycles is 5 to 15 times longer than the fourth purging times of the oxidants in the cycles after the initial number of cycles; and 
 the first purging times of the film-forming materials in the initial number of cycles is 5 to 10 times longer than the second purging times of the film-forming materials in the cycles after the initial number of cycles. 
 
     
     
       19. The method for manufacturing a semiconductor device according to  claim 17 , wherein the second insulating film is selected from the group consisting of HfO 2 , HfAlO x , HfSiO x , and nitrides thereof. 
     
     
       20. The method for manufacturing a semiconductor device according to  claim 17 , wherein the initial number of cycles is 10 to 20 cycles.